Search results for: parabolic wave guide

Authors: F. A. Rodríguez-Prada, W Gutierrez, I. D. Mikhailov

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We study the spectral properties of one-electron non-uniform crater-shaped quantum dot whose thickness is increased linearly with different slopes in different radial directions between the central hole and the outer border and which is deposited over thin wetting layer in the presence of the external vertically directed magnetic field. We show that in the adiabatic limit, when the crater thickness is much smaller than its lateral dimension, the one-particle wave functions of the electron confined in such structure in the zero magnetic field case can be found exactly in an analytical form and they can be used subsequently as the base functions in framework of the exact diagonalization method to study the effect of the wetting layer and an external magnetic field applied along of the grown axis on energy levels of one-electron non-uniform quantum dot. It is shown that both the structural non-uniformity and the increase of the thickness of the wetting layer provide a quenching of the Aharonov-Bohm oscillations of the lower energy levels.

Keywords: electronic properties, quantum rings, volcano shaped, wetting layer

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Authors: Shoji Mori, Kunito Okuyama

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Annular two phase flow is encountered in many industrial equipments, including flow near nuclear fuel rods in boiling water reactor (BWR). Especially, disturbance waves play important roles in the pressure drop, the generation of entrainments, and the dryout of the liquid film. Therefore, it is important to clarify the behavior of disturbance waves and base film. However, most of the previous studies have been performed under atmospheric pressure conditions that provides the properties of liquid and gas which are significantly different from those of a BWR. Therefore, the effect of properties in gas and liquid on liquid film characteristics should be clarified. In this paper we focus on the effect of gas-liquid density ratio on liquid film thickness characteristics. The experiments have been conducted at four density ratio conditions (ρL/ρG =763, 451, 231, and 31). As a result, it is found that and interfacial shear stress collapse not only tF ave but also tF max and tF min successfully under the same liquid mass flow rate conditions irrespective of ρL/ρG, and moreover a non-dimensional parameter tends to collapse tF max，tF ave，and tF min in the wide range of experimental conditions (ρL/ρG：31～763，We：10～1800，ReL:500 ～ 2200).

Keywords: two phase flow, liquid film, annular flow, disturbance wave

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Authors: Shaban Aly, Ali Al-Qahtani, Houari B. Khenous

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Synchronization is an important phenomenon commonly observed in nature. A system of periodically forced complex Duffings oscillators was introduced and shown to display chaotic behavior and possess strange attractors. Such complex oscillators appear in many problems of physics and engineering, as, for example, nonlinear optics, deep-water wave theory, plasma physics and bimolecular dynamics. In this paper, we study the remarkable phenomenon of chaotic synchronization on these oscillator systems, using impulsive synchronization techniques. We derive analytical expressions for impulsive control functions and show that the dynamics of error evolution is globally stable, by constructing appropriate Lyapunov functions. This means that, for a relatively large set initial conditions, the differences between the drive and response systems vanish exponentially and synchronization is achieved. Numerical results are obtained to test the validity of the analytical expressions and illustrate the efficiency of these techniques for inducing chaos synchronization in our nonlinear oscillators.

Keywords: complex nonlinear oscillators, impulsive synchronization, chaotic systems, global exponential synchronization

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Authors: S. H. Kazmi, T. Ahmed, K. Javed, A. Ghani

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In this paper static scheme of under-frequency based load shedding is considered for chemical and petrochemical industries with islanded distribution networks relying heavily on the primary commodity to ensure minimum production loss, plant downtime or critical equipment shutdown. A simplistic methodology is proposed for in-house implementation of this scheme using underfrequency relays and a step by step guide is provided including the techniques to calculate maximum percentage overloads, frequency decay rates, time based frequency response and frequency based time response of the system. Case study of FFL electrical system is utilized, presenting the actual system parameters and employed load shedding settings following the similar series of steps. The arbitrary settings are then verified for worst overload conditions (loss of a generation source in this case) and comprehensive system response is then investigated.

Keywords: islanding, under-frequency load shedding, frequency rate of change, static UFLS

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Authors: Hee Sun (Sunny) Choi, Gerhard Bruyns, Wang Zhang, Sky Cheng, Saijal Sharma

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This research addresses the need for a comprehensive framework that can guide the design and assessment of multi-level public spaces and public realms and their impact on the built environment. The study aims to understand and measure the neural mechanisms involved in this process. By doing so, it can lay the foundation for vertical and volumetric urbanism and ensure consistency and excellence in the field while also supporting scientific research methods for urban design with cognitive neuroscientists. To investigate these aspects, the paper focuses on the neighborhood scale in Hong Kong, specifically examining multi-level public spaces and quasi-public spaces within both commercial and residential complexes. The researchers use predictive Artificial Intelligence (AI) as a methodology to assess and comprehend the applicability of the urban design framework for vertical and volumetric urbanism. The findings aim to identify the factors that contribute to successful public spaces within a vertical living environment, thus introducing a new typology of public spaces.

Keywords: vertical urbanism, scientific research methods, spatial cognition, urban design guideline

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Authors: P. H. Mukti, I. Kurniawati, F. Oktaviansyah, A. D. Adhitya, N. Rachmadani, R. Corputty, G. Hendrantoro, T. Fukusako

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HF Communication system is one of the attractive fields among many researchers since it can be reached long-distance areas with low-cost. This long-distance communication can be achieved by exploiting the ionosphere as a transmission medium for the HF radio wave. However, due to the dynamic nature of ionosphere, the channel characteristic of HF communication has to be investigated in order to gives better performances. Many techniques to characterize HF channel are available in the literature. However, none of those techniques describe the HF channel characteristic in low-latitude regions, especially equatorial areas. Since the ionosphere around equatorial region has an ESF phenomenon, it becomes an important investigation to characterize the wideband HF Channel in low-latitude region. On the other sides, the appearance of software-defined radio attracts the interest of many researchers. Accordingly, in this paper a SDR-based channel measurement system is proposed to be used for characterizing the HF channel in low-latitude region.

Keywords: channel characteristic, HF communication system, LabVIEW, software-defined radio, universal software radio peripheral

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Authors: Ho Wen Hui, Azwina Wati Abdull Manaf, Asfarina Kartika Mohd Shakri

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The global trend of Fintech had taken the Malaysian shore by storm in recent years, thus making the studies and observations of its impacts more critical than ever. Additionally, Fintech has grown to become an unavoidable subject in the Islamic Banking and Finance (IBF) industry. In relation to that, this paper seeks to analyze the development of Fintech parallel with the IBF industry and its connection to Islamic economics. While the scarcity of studies on this area is apparent, it is found that there is a need to regulate the development of the Fintech Industry and its effects while analyzing the ramifications and positive effects of Fintech towards parties involved in IBF industry. This paper objectively studies the phenomenon of Islamic Fintech around the world as a whole as well as more specifically in Malaysia. The paper will then explore on the existing regulatory instruments in Malaysia, study their boundaries as well as limitations and contribute on possible reform to regulate Islamic Fintech in this jurisdiction. It is aimed that this paper will prompt and encourage more thorough studies to be conducted on the topic of Fintech which would subsequently contribute to a positive growth of the IBF industry worldwide.

Keywords: financial technology, FinTech, Islamic banking & finance, regulation

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Authors: Behrooz Balaei, Suzanne Wilkinson, Regan Potangaroa, Larry Abel, Philip McFarlane

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Water supply system failure has serious direct and indirect effects on people wellbeing. Post-disaster water system serviceability depends on a variety of factors from technical characteristics to social, economic, and organizational attributes of communities. This paper tests the organizational factors affecting water supply resilience to outline how these factors contributed to previous disasters. To do so, a framework is briefly introduced in this study to provide a clear guide to identify the significant relevant organizational factors. Then the factors affecting water serviceability following a disaster are outlines. Next, these factors are measured in the case of Tropical Cyclone Pam, which hit Vanuatu in March 2015. Reviewing the existing literature has also been carried out to obtain a comprehensive understanding of the background A site visit and a series of interviews have also been undertaken following the cyclone to collect site-specific data and information. In the end, the organizational factors were ranked to enable decision makers to identify significance of each factor compared to the others.

Keywords: water supply, resilience, organizational capacity, Vanuatu, Tropical Cyclone Pam

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Authors: Sunday Ofum Ogon

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The 1648 Westphalia Conference in Europe ushered in the state as the only legal entity with powers to engage in interstate relations on matters that bothers on the development need of her citizens. This epochal entry of the state reshaped global relations with the curtailment of the powers of individual and groups in external relations as the state became the only entity that acted on behalf of any individual or non-state actors like NGOs residing within the parameters of such a country. Thus, the paper interrogated the extent at which the state determines her Politico-Economic relations with regards to development and growth within the state. To achieve these objectives, the paper relied on documentary evidences wherein the qualitative descriptive method was used for data collection and analysis. The paper exploited the facilities of the Rentier State theory as a guide to the study. It was revealed at the end of the study that the 21st century global economic relations is largely determine by international organizations as exemplified by the World Bank and the International Monitory Fund (IMF) where their activities in the continent has undermined state sovereignty. Hence the paper recommended amongst others that states should look inward for development strategies rather than relying on handout from supra-national organizations which has infringe on their sovereignty.

Keywords: State , Global , Rentier state, Twenty-First Century

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Authors: Kiran Datta, Daniella Holland-Hart, Anthony Byrne

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Introduction: Oesophago-gastric (OG) cancers are the fifth commonest in the UK, accounting for over 12,000 deaths each year. Most patients will present at later stages of the disease, with only 21% of patients with stage 4 disease surviving longer than a year. As a result, many patients are unsuitable for curative surgery and instead receive palliative treatment to improve prognosis and symptom burden. However, palliative chemotherapy can result in significant toxicity: almost half of the patients are unable to complete their chemotherapy regimen, with this proportion rising significantly in older and frailer patients. In addition, clinical trials often exclude older and frailer patients due to strict inclusion criteria, meaning there is limited evidence to guide which patients are most likely to benefit from palliative chemotherapy. Inappropriate chemotherapy administration is at odds with the goals of palliative treatment and care, which are to improve quality of life, and this also represents a significant resource expenditure. This literature review aimed to examine and appraise evidence regarding treatment resilience in order to guide clinicians in identifying the most suitable candidates for palliative chemotherapy. Factors influencing treatment resilience were assessed, as measured by completion rates, dose reductions, and toxicities. Methods: This literature review was conducted using rapid review methodology, utilising modified systematic methods. A literature search was performed across the MEDLINE, EMBASE, and Cochrane Library databases, with results limited to papers within the last 15 years and available in English. Key inclusion criteria included: 1) participants with either oesophageal, gastro-oesophageal junction, or gastric cancers; 2) patients treated with palliative chemotherapy; 3) available data evaluating the association between baseline participant characteristics and treatment resilience. Results: Of the 2326 papers returned, 11 reports of 10 studies were included in this review after excluding duplicates and irrelevant papers. Treatment resilience factors that were assessed included: age, performance status, frailty, inflammatory markers, and sarcopenia. Age was generally a poor predictor for how well patients would tolerate chemotherapy, while poor performance status was a better indicator of the need for dose reduction and treatment non-completion. Frailty was assessed across one cohort using multiple screening tools and was an effective marker of the risk of toxicity and the requirement for dose reduction. Inflammatory markers included lymphopenia and the Glasgow Prognostic Score, which assessed inflammation and hypoalbuminaemia. Although quick to obtain and interpret, these findings appeared less reliable due to the inclusion of patients treated with palliative radiotherapy. Sarcopenia and body composition were often associated with chemotherapy toxicity but not the rate of regimen completion. Conclusion: This review demonstrates that there are numerous measures that can estimate the ability of patients with oesophago-gastric cancer to tolerate palliative chemotherapy, and these should be incorporated into clinical assessments to promote personalised decision-making around treatment. Age should not be a barrier to receiving chemotherapy and older and frailer patients should be included in future clinical trials to better represent typical patients with oesophago-gastric cancers. Decisions regarding palliative treatment should be guided by these factors identified as well as patient preference.

Keywords: frailty, oesophago-gastric cancer, palliative chemotherapy, treatment resilience

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Authors: Abdelhamid Louliej, Younes Jabrane

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Satellites are becoming indispensable assets to fifth-generation (5G) new radio architecture, complementing wireless and terrestrial communication links. The combination of satellites and 5G architecture allows consumers to access all next-generation services anytime, anywhere, including scenarios, like traveling to remote areas (without coverage). Nevertheless, this solution faces several challenges, such as a significant propagation delay, Doppler frequency shift, and high Peak-to-Average Power Ratio (PAPR), causing signal distortion due to the non-linear saturation of the High-Power Amplifier (HPA). To compensate for HPA non-linearity in 5G satellite transmission, an efficient pre-distorter scheme using Neural Networks (NN) is proposed. To assess the proposed NN pre-distorter, two types of HPA were investigated: Travelling Wave Tube Amplifier (TWTA) and Solid-State Power Amplifier (SSPA). The results show that the NN pre-distorter design presents EVM improvement by 95.26%. NMSE and ACPR were reduced by -43,66 dB and 24.56 dBm, respectively. Moreover, the system suffers no degradation of the Bit Error Rate (BER) for TWTA and SSPA amplifiers.

Keywords: satellites, 5G, neural networks, HPA, TWTA, SSPA, EVM, NMSE, ACPR

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Authors: Hongmei Chi

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The Blockchain has become a necessity for many different societal industries and ordinary lives including cryptocurrency technology, supply chain, health care, public safety, education, etc. Therefore, training our future blockchain developers to know blockchain programming vulnerability and I.T. students' cyber security is in high demand. In this work, we propose a framework including learning modules and hands-on labs to guide future I.T. professionals towards developing secure blockchain programming habits and mitigating source code vulnerabilities at the early stages of the software development lifecycle following the concept of Secure Software Development Life Cycle (SSDLC). In this research, our goal is to make blockchain programmers and I.T. students aware of the vulnerabilities of blockchains. In summary, we develop a framework that will (1) improve students' skills and awareness of blockchain source code vulnerabilities, detection tools, and mitigation techniques (2) integrate concepts of blockchain vulnerabilities for IT students, (3) improve future IT workers’ ability to master the concepts of blockchain attacks.

Keywords: software vulnerability detection, hands-on lab, static analysis tools, vulnerabilities, blockchain, active learning

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Authors: L. Abubakar, B. M. Sokoto, I. U. Mohammed, M. S. Na’allah, A. Mohammad, A. N. Garba, T. S. Bubuche

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Onion (Allium cepa var. cepa L.), is the most important species of the Allium group belonging to family Alliaceae and genus Allium. It can be regarded as the single important vegetable species in the world after tomatoes. Despite the similarities, which bring the species together, the genus is a strikingly diverse one, with more than five hundred species, which are perennial and mostly bulbous plants. Out of these, only seven species are in cultivation, and five are the most important species of the cultivated Allium. However, Allium cepa (onion) and Allium sativum (Garlic) are the two major cultivated species grown all over the world of which the onion crop is the most important. Heritability defined as the proportion of the observed total variability that is genetic, and its estimates from variance components give more useful information of genotypic variation from the total phenotypic differences and environmental effects on the individuals or families. It therefore guide the breeder with respect to the ease with which selection of traits can be carried out. Heritability estimates guide the breeder with respect to ease of selection of traits while correlations suggest how selection among characters can be practiced. Correlations explain relationship between characters and suggest how selection among characters can be practiced in breeding programmes. Highly significant correlations have been reported, between yield, maturity, rings/bulb and storage loss in onions. Similarly significant positive correlation exists between total bulb yield and plant height, leaf number/plant, bulb diameter and bulb yield/plant. Moderate positive correlations have been observed between maturity date and yield, dry matter content was highly correlated with soluble solids, and higher correlations were also observed between storage loss and soluble solids. The objective of the study is to determine heritability estimates and correlations for characters among onion cultivars of North Western Nigeria. This is envisaged will assist in the breeding of superior onion cultivars within the zone. Thirteen onion cultivars were collected during an expedition covering north western Nigeria and Southern part of Niger Republic during 2013, which are areas noted for onion production. The cultivars were evaluated at two locations; Sokoto, in Sokoto State and Jega in Kebbi State all in Nigeria during the 2013/14 onion season (dry season) under irrigation. Combined analysis of the results revealed fresh bulb yield is highly significantly positively correlated with bulb height and cured bulb yield, and significant positive correlation with plant height and bulb diameter. It also recorded significant negative correlation with mean No. of leaves/plant and non significant negative correlation with bolting %. Cured bulb yield (marketable yield) had highly significant positive correlation with mean bulb weight and fresh bulb yield/ha, with significant positive correlation with bulb height. It also recorded highly significant negative correlation with No. of leaves/plant and significant negative correlation with bolting % and non significant positive correlation with plant height and non significant negative correlation with bulb diameter. High broad sense heritability estimates were recorded for plant height, fresh bulb yield, number of leaves/plant, bolting % and cured bulb yield. Medium to low broad sense heritabilities were also observed for mean bulb weight, plant height and bulb diameter.

Keywords: correlation, heritability, onions, North Western Nigeria

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Authors: Faizan Ahmad, Jenna Wong

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Time lag between peak values of horizontal and vertical seismic waves is a well-known phenomenon. Horizontal and vertical seismic waves, secondary and primary waves in nature respectively, travel through different layers of soil and the travel time is dependent upon the medium of wave transmission. In seismic analysis, many standardized codes do not require the actual vertical acceleration to be part of the analysis procedure. Instead, a factor load addition for a particular site is used to capture strength demands in case of vertical excitation. This study reviews the effects of vertical accelerations to analyze the behavior of a linearly rubber isolated structure in different time lag situations and frequency content by application of historical and simulated ground motions using SAP2000. The response of the structure is reviewed under multiple sets of ground motions and trends based on time lag and frequency variations are drawn. The accuracy of these results is discussed and evaluated to provide reasoning for use of real vertical excitations in seismic analysis procedures, especially for isolated structures.

Keywords: seismic analysis, vertical accelerations, time lag, isolated structures

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Authors: Raymond Yudhi Purba, Levy Olivia Nur, Radial Anwar

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This research presents the design and measurement of a skew planar wheel antenna that is used to visualize the first person view perspective of unmanned aerial vehicles. The antenna has been designed using CST Studio Suite 2019 to have voltage standing wave ratio (VSWR) ≤ 2, return loss ≤ -10 dB, bandwidth ≥ 100 MHz to covering outdoor access point band from 5.725 to 5.825 GHz, omnidirectional radiation pattern, and elliptical polarization. Dimensions of skew planar wheel antenna have been modified using parameter sweep technique to provide good performances. The simulation results provide VSWR 1.231, return loss -19.693 dB, bandwidth 828.8 MHz, gain 3.292 dB, and axial ratio 9.229 dB. Meanwhile, the measurement results provide VSWR 1.237, return loss -19.476 dB, bandwidth 790.5 MHz, gain 3.2034 dB, and axial ratio 4.12 dB.

Keywords: skew planar wheel, cloverleaf, first-person view, unmanned aerial vehicle, parameter sweep

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Authors: Loke Kean Koay, Mani Maran Ratnam

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A mechanically-resonant torsional spring scanner was developed in a recent study. Various methods were developed to improve the angular displacement of the scanner while maintaining the scanner frequency. However, the effects of rotor magnet radial position on scanner characteristics were not well investigated. In this study, the relationships between the magnet position and the scanner characteristics such as natural frequency, angular displacement and stress level were studied. A finite element model was created and an average deviation of 3.18% was found between the simulation and experimental results, qualifying the simulation results as a guide for further investigations. Three magnet positions on the transverse oscillating suspended plate were investigated by finite element analysis (FEA) and one of the positions were selected as the design position. The magnet position with the longest distance from the twist axis of the mirror was selected since it attains minimum stress level while exceeding the minimum critical flicker frequency and delivering the targeted angular displacement to the scanner.

Keywords: torsional scanner, design optimization, computer-aided design, magnet position variation

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Authors: Stephen Coandadiputra, Chrestella Carissa

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Technology is created to simplify human’s life. One of current technology which being called as the second wave internet generation is the internet of things. Internet of things lets thousands of devices connected each other. In today's marketing world, IOT has brought customer into the next level which helping the customer to shorten every transaction they are conducting from traditional approach to sophisticated approach. However, the implementation of technology has always obstacles. The objective of this paper is to explore the determinants of customer to accepts such technology like the internet of things within their transaction. According to TAM (Technology Acceptance Model), researcher constructs the acceptance of internet of things based on perceived usefulness, perceived ease of use and trust and social factor and the two customer characteristics: perceived enjoyment and perceived behavioral control. This research uses exploratory research design which being facilitated by spreading questionnaire to 145 T-cash users in Jakarta and in its suburban region. At least, 190 samples were observed and questioned accordingly. All the collected data will be analyzed using Lisrel.

Keywords: behavioral intention to use, internet of things, near field communication, technology acceptance model

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Authors: Sayed Kifayat Shah, Tang Zhongjun, Arfa Tanveer

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This study explores the significant heatwave effect on stock return and volatility. Using an ARCH/GARCH approach, it examines the relationship between the heatwave of Karachi, Islamabad, and Lahore on the KSE-100 index. It also explores the impact of heatwave on returns of the pharmaceutical and electronics industries. The empirical results confirm that that stock return is positively related to the heat waves of Karachi, negatively related to that of Islamabad, and is not affected by the heatwave of Lahore. Similarly, pharmaceutical and electronics indices are also positively related to heatwaves. These differences in results can be ascribed to the change in the behavior of the residents of that city. The outcomes are useful for understanding an investor's behavior reacting to weather and fluxes in stock price related to heatwave severity levels. The results can support investors in fixing biases in behavior.

Keywords: ARCH/GARCH model, heat wave, KSE-100 index, stock market return

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Authors: A. Didaoui, N. Benhalima, M. Elkeurti, A. Chouaih, F. Hamzaoui

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The monomer and dimer structures of the title molecule have been obtained from density functional theory (DFT) B3LYP method with 6-31G (d,p) as basis set calculations. The optimized geometrical parameters obtained by B3LYP/6-31G (d,p) method show good agreement with xperimental X-ray data. The polarizability and first order hyperpolarizabilty of the title molecule were calculated and interpreted. the intermolecular N–H•••O hydrogen bonds are discussed in dimer structure of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 03 set of quantum chemistry codes. The predicted frontier molecular orbital energies at B3LYP/6-31G(d,p) method set show that charge transfer occurs within the molecule. The frontier molecular orbital calculations clearly show the inverse relationship of HOMO–LUMO gap with the total static hyperpolarizability. The results also show that N-(2-Methylphenyl)-2-nitrobenzenesulfonamide molecule may have nonlinear optical (NLO) comportment with non-zero values.

Keywords: DFT, Gaussian 03, NLO, N-(2-Methylphenyl)-2-nitrobenzenesulfonamide

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Authors: Ana Sofia Saldanha

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The globalization is changing the translation world day after day, year after year. The need to know more about new technologies, clients, companies and social networks is becoming more and more demanding and competitive. The recently graduated translators usually do not know where to go, what to do or even who to contact to start their careers in translation. It is well known that there are innumerous webinars, books, blogs, webpages and even Facebook pages indicating what to do, what not to do, rates, how your CV should look like, etc. but are these pieces of advice of real translators? Translators, who work daily with clients, who understand their demands, requests, questions? As far as today`s trends, the answer is NO. Most of these pieces of advice are just theoretical and far away from the real translation world. Therefore, mentoring is becoming a very important tool to help and guide new translators starting their career. An effective and well-oriented mentoring is a powerful way to orient these translators on how to create their CVs, where to send CVs, how to approach clients, how to answer emails and how to negotiate rates in an efficient way. Mentoring is crucial when properly delivered by professional and experienced translators, to help developing careers. The advice and orientation sessions are almost a 'weapon' to destroy the barriers created by opinions, by influences or even by universities. This new trend is the future path of new translators and is the future of the translation industry and professionals, however minds and spirits need to be opened and engaged in this new way of developing skills.

Keywords: mentoring, translation, translators, orientation, professional path

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Authors: Kaycee L. Bills

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Adolescents and youth who are members of a minority group are more likely to experience higher rates of bullying in comparison to other student demographics. Specifically, adolescents with intellectual disabilities are a minority population that is more susceptible to experience unfair treatment in social settings. This study employs the 2015 Wave of the National Crime Victimization Survey – School Crime Supplement (NCVS/SCS) longitudinal dataset to explore bullying rates experienced among adolescents with intellectual disabilities. This study uses chi-square testing and a logistic regression to analyze if having a disability influences the likelihood of being bullied in comparison to other student demographics. Results of the chi-square testing and the logistic regression indicate that adolescent students who were identified as having a disability were approximately four times more likely to experience higher bullying rates in comparison to all other majority and minority student populations. Thus, it means having a disability resulted in higher bullying rates in comparison to all student groups.

Keywords: disability, bullying, social work, school bullying

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Authors: N. Khelloul, N. Benhalima, A. Chouaih, F. Hamzaoui

Abstract:

The monomer and dimer structures of the title molecule have been obtained from density functional theory (DFT) B3LYP method with 6-31G (d,p) as basis set calculations. The optimized geometrical parameters obtained by B3LYP/6-31G (d,p) method shows good agreement with experimental X-ray data. The polarizability and first order hyperpolarizabilty of the title molecule were calculated and interpreted. The intermolecular N–H•••O hydrogen bonds are discussed in dimer structure of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 09 set of quantum chemistry codes. The predicted frontier molecular orbital energies at B3LYP/6-31G(d,p) method set show that charge transfer occurs within the molecule. The frontier molecular orbital calculations clearly show the inverse relationship of HOMO–LUMO gap with the total static hyperpolarizability. The results also show that 2-Chloro-N-(2-methylphenyl) benzamide 2 molecule may have nonlinear optical (NLO) comportment with non-zero values.

Keywords: DFT, HOMO, LUMO, NLO

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Authors: P.Kiruthika, K. Ramani

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This paper presented the design and advancement of a single-phase 27-level Hybrid Multilevel DC-AC Converter interfacing with Photo Voltaic. In this context, the Multicarrier Pulse Width Modulation method can be implemented in 27-level Hybrid Multilevel Inverter for generating a switching pulse. Perturb & Observer algorithm can be used in the Maximum Power Point Tracking method for the Photo Voltaic system. By implementing Maximum Power Point Tracking with three separate solar panels as an input source to the 27-level Hybrid Multilevel Inverter. This proposed method can be simulated by using MATLAB/simulink. The result shown that the proposed method can achieve silky output wave forms, more flexibility in voltage range, and to reduce Total Harmonic Distortion in medium-voltage drives.

Keywords: Multi Carrier Pulse Width Modulation Technique (MCPWM), Multi Level Inverter (MLI), Maximum Power Point Tracking (MPPT), Perturb and Observer (P&O)

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Authors: Adamu Mudi, Ibrahim Wahab Fawole, Abubakar Abba Kolo

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In this research paper, we present a microcontroller-based liquid level controller that identifies the various levels of a liquid, carries out certain actions, and is capable of communicating with the human being and other devices through the GSM network. This project is useful in ensuring that a liquid is not wasted. It also contributes to the internet of things paradigm, which is the future of the internet. The method used in this work includes designing the circuit and simulating it. The circuit is then implemented on a solderless breadboard, after which it is implemented on a strip board. A C++ computer program is developed and uploaded into the microcontroller. This program instructs the microcontroller on how to carry out its actions. In other to determine levels of the liquid, an ultrasonic wave is sent to the surface of the liquid similar to radar or the method for detecting the level of sea bed. Message is sent to the phone of the user similar to the way computers send messages to phones of GSM users. It is concluded that the routine of observing the levels of a liquid in a tank, refilling the tank when the liquid level is too low can be entirely handled by a programmable device without wastage of the liquid or bothering a human being with such tasks.

Keywords: Arduino Uno, HC-SR04 ultrasonic sensor, internet of things, IoT, SIM900 GSM module

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Authors: E. Sener, O. Isik, E. Eroglu, U. Sahin

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The main idea is to solve the system of Maxwell’s equations in accordance with the causality principle to get the energy quantities via Airy functions in a hollow rectangular waveguide. We used the evolutionary approach to electromagnetics that is an analytical time-domain method. The boundary-value problem for the system of Maxwell’s equations is reformulated in transverse and longitudinal coordinates. A self-adjoint operator is obtained and the complete set of Eigen vectors of the operator initiates an orthonormal basis of the solution space. Hence, the sought electromagnetic field can be presented in terms of this basis. Within the presentation, the scalar coefficients are governed by Klein-Gordon equation. Ultimately, in this study, time-domain waveguide problem is solved analytically in accordance with the causality principle. Moreover, the graphical results are visualized for the case when the energy and surplus of the energy for the time-domain waveguide modes are represented via airy functions.

Keywords: airy functions, Klein-Gordon Equation, Maxwell’s equations, Surplus of energy, wave boundary operators

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Authors: Mahani Razali, Abd Halim Masnan, Nordin Mamat, Seah Siok Peh

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This research is based on three main objectives which are to identify children`s social interaction behaviour during computer play activities, teacher’s role and to explore teacher’s beliefs, views and knowledge about computers use in four Malaysian pre-schools.This qualitative study was carried out among 25 pre-school children and three teachers as the research sample. The data collection procedures involved structured observation which was to identify social interaction behavior among pre-school children through computer play activities; as for semi-structured interviews, it was done to study the perception of the teachers on the acquired of social interaction behavior development among the children. A variety of patterns can be seen within the peer interactions indicating that children exhibit a vast range of social interactions at the computer, and they varied each day. The findings of this study guide us to certain conclusions, which have implications in understanding the phenomena of how computers were used and how its relationship to the children’s social interactions emerge in the four Malaysian preschools. This study provides evidence that the children’s social interactions with peers and adults were mediated by the engagement of the children in the computer environments.

Keywords: computer, play, preschool, social interaction

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Authors: DucTho Le, Duy Kien Dao, Quoc Tinh Bui, Haidang Phan

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The article is concerned with the motion of ultrasonic guided waves in a unidirectional fiber-reinforced composite plate under acoustic sources. Such unidirectional composite material has orthotropic elastic properties as it is very stiff along the fibers and rather compliant across the fibers. The dispersion equations of free Lamb waves propagating in an orthotropic layer are derived that results in the dispersion curves. The connection of these equations to the Rayleigh-Lamb frequency relations of isotropic plates is discussed. By the use of reciprocity in elastodynamics, closed-form solutions of elastic wave motions subjected to time-harmonic loads in the layer are computed in a simple manner. We also consider the problem of Lamb waves generated by a set of time-harmonic sources. The obtained computations can be very useful for developing ultrasound-based methods for nondestructive evaluation of composite structures.

Keywords: lamb waves, fiber-reinforced composite plates, dispersion equations, nondestructive evaluation, reciprocity theorems

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Authors: Alessio Mastrorillo, Giuseppe Silvi, Francesco Scagliola

Abstract:

In this work, we introduce an Ambisonics decoder with an implementation of the C-format, also called Super Stereo. This format is an alternative to conventional stereo and binaural decoding. Unlike those, this format conveys audio information from the horizontal plane and works with stereo speakers and headphones. The two C-format channels can also return a reconstructed planar B-format. This work provides an open-source implementation for this format. We implement an all-pass filter for signal quadrature, as required by the decoding equations. This filter works with six Biquads in a cascade configuration, with values for control frequency and quality factor discovered experimentally. The phase response of the filter delivers a small error in the 20-14.000Hz range. The decoder has been tested with audio sources up to 192kHz sample rate, returning pristine sound quality and detailed stereo image. It has been included in the Envelop for Live suite and is available as an open-source repository. This decoder has applications in Virtual Reality and 360° audio productions, music composition, and online streaming.

Keywords: ambisonics, UHJ, quadrature filter, virtual reality, Gerzon, decoder, stereo, binaural, biquad

Procedia PDF Downloads 77

Authors: Kwame Kodua-Ntim

Abstract:

The study explored the authors self-archiving to create awareness of open-access institutional repositories in universities. The qualitative approach of the study was informed by the interpretive paradigm as well as the case research design. The target population for the study was all twelve (12) open-access institutional repositories managers and administrators purposively selected from the five (5) universities in Ghana. The universities were chosen since they were the only ones listed in the Directory of Open Access Repositories. Interviews were conducted using a semi-structured interview guide and data were analyzed using thematic analysis. The study revealed that academics had some information about self-archiving in open-access institutional repositories and university libraries with open-access institutional repositories were using DSpace software. Managers and administrators of open-access institutional repositories mediated content uploaded and believed that author self-archiving could improve awareness of open-access institutional repositories. The study recommended that universities should fully implement the author’s self-archiving protocol, and academics should be trained to be able to upload research works onto open-access institutional repositories. Furthermore, the university and university library should provide rigorous policies on author self-archiving and incentives for author self-archiving in the open access institutional repositories.

Keywords: author, awareness, institutional repositories, open access, open archive, self-archiving

Procedia PDF Downloads 63

Authors: Young-Doo Kwon, Seong-Hwa Jun, Dong-Jin Lee, Hyung-Seok Lee

Abstract:

Ball joints support and guide certain automotive parts that move relative to the frame of the vehicle. Such ball joints are covered and protected from dust, mud, and other interfering materials by ball-joint boots made of rubber—a flexible and near-incompressible material. The boots may experience twisting and bending deformations because of the motion of the joint arm. Thus, environmental and endurance tests of ball-joint boots apply both bending and twisting deformations. In this study, environmental and endurance testing was simulated via the finite element method performed by using a commercial software package. The ranges of principal stress and principal strain values that are known to directly affect the fatigue lives of the parts were sought. By defining these ranges, the number of iterative tests and modifications of the materials and dimensions of the boot can be decreased. Therefore, instead of performing actual part tests, manufacturers can perform standard fatigue tests in trials of different materials by applying only the defined range of stress or strain values.

Keywords: boot, endurance tests, rubber, FEA

Procedia PDF Downloads 250